Double apron festoon drier



Feb. 9, 1937. A. o. HURXTHAL DOUBLE APRON FESTOON DRIER Filed June l5, 1933 Patented Feb. 9, 1937 UNITED ASTATES Arnon rEsTooN Dama Hurxthal, Philadelphia, Pa., assignor DQUBLE l Alpheus 0.

to Proctor & Schwartz, Incorporated,

PATENT OFFICE Philadelphia, Pa., a corporation of ,Pennsylvania Application 4Jnnel, 1933, Serial No. 6l6,000

11 (rutinas.` (Cl. :i4-12) f perpendicular to and through the conveyer and thelayerof material carriedthereby. y v In a drying apparatus of this type an extremely long drying chamber is frequently required,lwith the conveyer traveling continually at a moderate rate of speed-consistent with the rate at which the conveyer may be properlyloaded, invorder to obtain maximum capacity and delivery and at of the mate-` the same time insure proper drying rial being handled. v

lAs the length of the machine increases the initial installation and maintenancel costs increase proportionately as also does the amount of floor space required to accommodate the machine. As the length of the machine increases the' heat losses also increase requiring an additional amount of piping or otherinternal radiation to compensate for such heat losses.`

The object of the present invention is to reduce the length of the drying chamber without sacrificing efficiency or capacity and at the. same i time reduce the initial installation, maintenance and operating costs, and to eliminate such other disadvantages as are incidental to the use of the relatively long drying chamber.`

The present invention primarily contemplates the elimination of the strictly horizontal conveyer in the drying chamber by the provision` of suitable means projecting laterally beyondlthe side edges of the conveyer, whereby the conveyer may be hung in suitably spaced festoons on suitable carriers moving horizontally in and through the drying chamber, whereby thelength of the drying chamber may be accordingly reduced, the door spacelikewise reduced,.and the amount of radiation necessaryfor maintaining a predetermined temperature within the drying chamber reduced toa minimum as a result of the reduction in the heat vlosses `effected by the use of the shorter drying chamber.

In order to prevent slipping of the layer of material on the inclined portions of the festooned conveyer the present invention furthercontemplates the use ofmeans projecting upwardly from the material-carrying face of the conveyer for entrance into the layer of material thereon, whereby relative movement between the conveyer and the layer of material is eliminated or reduced to a negligible degree.

In order to obviate tumblingV of the material on the` conveyer along the inclined portions of the festoons the present invention contemplates the provision of a holding element disposed in superposed substantially parallel relation to the supporting conveyer and resting on the layer of kmaterial disposed intermediate the two.

For purposes ofemciency, the holding element 'is preferably in theform of an endless belt of `a. foraminous nature, as is the carrying conveyer,

in order to permit free circulation of the drying medium through the superposed elements and the layer of material held therebetween.

As a result of the use of the hold-down belt, the drying medium' may be circulated lin both directions perpendicular to the layer of material or transversely thereof in order to keep the ma'` terial in a light, fluffy condition free of packing.

The holding belt is preferably automatically laid on the material at or adjacent the feed end of the drier after theI material has been spread on the carrying element and before the formation oi. the festoons; and removed from the material, automatically, after the material has been dried to the desired extent, preferably after the two superposed elements have been drawn out of the festoons adjacent the delivery end of the drier. However, in some instances the holddown element may be withdrawn at any desired place in the course of travel of the conveyer and hold-,down element at which the material has dried and become more or less matted or interlocked to such an extent that it has attained the form of a continuous web or sheet wherein the tendency of the material to tumble in the festoons is practically nil.

In some instances, for example when the material is of a relatively coarse nature, the anti-slip means, projecting from' the carrying face of the supporting .conveyer into the layer of material thereon, may be eliminated when the hold-down belt is employed; and in other instances, for example when thematerial is of a` relatively ne nature, both the supporting conveyer and the hold-down belt may be equipped Wlththe antislip means, whichpreferably take the form of spikes or teeth. 1

The construction and operation of the mechanism forming the subject ofthe present invention will be fully disclosed hereinafter, reference being had to the accompanying drawing, of which:

Fig. 1 is a diagrammatic longitudinal side elevation of a loose material drier made in accordance with the principles of the present invention; and

Fig. 2 is a View similar to Fig. 1, illustrating the anti-slip means on both the supporting conveyer and the hold-down'belt.

As shownV` in the drawing', the driericomprises a having circulating fans 3, 3 located at the top i.. of the drying chamber for circulating air through`v the heating and drying chambers, to maintain the-circulating air at a predeterminedtemperature for drying material carried through thedry-:-

ing chamber longitudinally thereof.

falfa as 'it comes from the eld and beforeit is baled forshpping.

The materiaalr is supported in andv carried throughthe drying chamber 2 byv and on' one face of an endless foraminous belt or'apron 5', which at spaced intervals longitudinally thereof is p rovided with transversely extendingwsupports or girts ,6, which are securedV thereto and extend'laterally beyond the @opposite side edges thereof respectively 1 o The supportingfbelt or apron 5'passes around a guide roller I disposed outside and' spaced'frorn one end ofthe casing I adjacent the base line of the. casing; and upwardly in an inclined plane;- as indicated at 8, toiand overa, vfeed roller or drumIIljdisposed adjacent thetop and one end of the cafSili'g IJ The supporting apron 5 is fed into the casing y feeding of the apron 5v into the casing I, by whichv the spacing of the festoons A, A is'lgove'rned.

VThe apron 5 is drawn out of the festoons A, A successively "by a drum .I5 similar to and having the Isaine' surface speed as the feed drum I0, whereby the apron 5 is removed from the casing I at the delivery end thereof at the same rate of speed at which it isfed into the opposite end of the casing by the feed drum I0.

'I'he carrier chains II may be driven at a predetermined rate of speed relative to the feed and discharge of the apron 5, by means of. sprockets I3 secured to the shaft I4 of thezdis'charge drum I5 while the'drums I0 and I5 may be synchronously d rivenby `any `suitable means, not shown. The apron 5, ,after leaving the discharge drum I5, passes around guide rolls '8 and 5 back"to the first mentioned guide roll 1 at the feed end of the casing I, either through` the bottom of the casing as shown, or inal channel provided below the base of the casing as desired.

The materialto be dried is fed to 'and spread on the conveyer apron 5, in the present instance,

by a feed hopper I6 provided with an elevator apron I'I which receives the material from a conveyer I8 at the bottom of the hopper and delivers it to the top of the hopper between the rear wall I9 thereof and an inclined front wall 20, the lower edge of which is disposed slightly above the carrying -face of ythe apron 5 to prevent the material from slidingv down the incline 8 of the apron 5, while the lower edge of the rearwall I9 of the hopper is spaced above the carrying face of the apron 5 to spread the ma- `terialthereon `in "'a uniform layer of predeter- :mined thickness.

The materialindicated at .'r, is carried upwardly by the inclinedportion 8 of the apron 5 and immediately behind the rear wall I9 of the loading hopper I6 the hold-down apron 25 is 'flaidgonztop of the layer of material :I: by a guide roll 24, from which the hold-down apron travels forward andover the feed drum I0 with thc conveyer apron 5 resting on the layer of ma- Inthe present instance thematerial to be dried f terial a: in Isuperposed spaced relation to the is of a relative loose character, the present machine being particularly adapted for drying alconveyer apron 5, maintaining' this relation to the conveyer apron 5 and the layer of material a: as the two are fed into'the casing I and formed intofestoonson the carrier chains II, the holddown apron 25 being formed into festoons A1, A1

'l which respectively agree with the festoons A, A

of the conveyer 5. e y

At the delivery end of the casing I the conveyer apron 5 and the hold-down apron 25 pass around the delivery drum I5, whereupon the conveyer 'apron 5fwith the layer of material a:

thereon passesdownwardly to the guide roll 8,

where the layer of'material :c is dumped into a chute 26 which may deliver the material to 'a baler'orv other suitable device for future handling, while the hold-down apron 25 passes upwardly around `afguide roll 2l and a pair of guide rolls 22 and 23 to the guide roll 24 at the rear end 0f the' feed hopper'IB.

The hold-down Vapron 25 may be driven at the same rate of speed as the feed drum I0 to keep the two -in synchronization by driving any or'all' ofthe lrolls 2I, 22, 23 and 24, from any suitable source, not shown, but in some instances the friction of the material m against theunder surface of the hold-down apron 25 is sufcient to drive the apron 25 at the same rate of speed as the conveyer apron 5.

As noted above one .or the other or both the aprons 5 and-25 may be provided with anti-slip means to maintain the layer of material :r-

against movement relative to the apron 5 and for this purpose Fig'. 2 illustrates each ofthe aprons 5 and '25 as beingfprovided with upwardly extending pins `or spikes 30 and 3I respectively which projectv into the layer of material a: carried bythe conveyer apron 5, thereby holding the material against any substantial movement relative to the apron 5 as the latter is formed into the festoons A, A.

In cases where the hold-down apron is also used and is provided with the pins 3| such pins preferably alternate with the pins 30 of the conveyer apron 5, and in such a case the pins 3| obtain sufiicient purchase in the layer of material a: as to drive the apron 25 without other mechanical `power being applied to the guide rolls 2 I, etc.

In'order to prevent slippage of the girts Ii, 6 onl the (carrier chains II, spaced links of said chains may be equipped with pockets to receive the vprojecting ends of the girts, thereby definitely spacing the girts uniformly on the carrier chains Il.

I claim: Y

1. The combination in a conveyer oi' a pair of freely separable superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, and means for supporting, maintaining and transporting said apronsupporting means in said laterally spaced relation.

2. The combination of a pair of superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, and means for forming said aprons and interposed material simultaneously into a festoon at one end of said series.

3. The combination of a pair of superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, means for forming said aprons and interposed material simultaneously into a festoon at one end of said series, and means for withdrawing said aprons and interposed material simultaneously from a festoon at the opposite end of said series.

4. The combination of a pair of superposed vertically spaced substantially parallelI aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, means for forming said aprons and interposed material simultaneously into a festoon at one end of said series, means for withdrawing said aprons and interposed material simultaneously from a festoon at the opposite end of said series, and means for conveying said series of festoons bodily in said inert state from said forming to said withdrawing means.

5. The combination of a pair of superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, means for forming said aprons and interposed material simultaneously intoa festoon at one end of said series, means for applying said layer of material to one of said aprons `prior tothe formation of said aprons into said festoon. and means for applying the second apron to said layer of material intermediate the material-applying means and the apron-festooning means.

6. The combination of a pair of superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, means for forming said aprons and interposed material simultaneously into a festoon at one end of said series, means for withdrawing said aprons and interposed material simultaneously from a festoon at the opposite end of said series, means for applying said layer of material to one of said aprons prior to the formation of said aprons into said festoon, means for applying the second apron to said layer of material intermediate the material-applying means and the apron-festooning means, and means for removing one of said aprons from said layer of material adjacent said withdrawing means to permit discharge of the material from the other of said aprons.

7. 'I'he combination of a pair of endless aprons, means for loading one of said aprons at a predetermined point in the endless course of travel thereof with a layer of loosematerial, means for applying a portion of the second apron to said layer of material in vertically spaced superposed and substantially parallel relation to the loaded portion of the first said apron, laterally spaced means for supporting said portions of said aprons and said interposed layer of material in a series of inert ,festoons depending from and hanging freely between said laterally spaced means, means for forming said apron portions and said interposedlayer of material into a festoon at one end of said series, means for withdrawing said aprons and said layer of material from a festoon at the opposite end of said series, means for conveying said series of festoons bodily in said inert state from said forming to said withdrawing means, means for separating the aprons from said interposed layer of material, and means for respectively guiding said separated aprons to said loading and applying means respectively.

8. The combination in a conveyer of a pair of freely separable superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely betweensaid laterally spaced means, and means extending from each of said aprons into the interposed layer of materia] for preventing shifting of the material relative to the confining aprons in the depending portions of said festoons.

9. The combination in a conveyer of a pair of freely separable superposed vertically spaced substantially parallel aprons for confining a layer of loose material therebetween, laterally spaced means for supporting said aprons and interposed material in a series of inert festoons depending from and hanging freely between said laterally spaced means, and means extending from'v one of said aprons into the interposed layer of material for preventing shifting of the material relative to the confining aprons in the depending portions of said festoons.

10. The combination in a conveyer of an apron arranged to receive a superposed layer of loose material, laterally spaced means for supporting the apron and the superposed layer of material in a series of inert festoons depending from and hanging freely between said laterally spaced means, means for bodily transporting -sad inert festoons longitudinally of said laterally spaced supporting means, and means projecting from the apron into the layer of material thereon for preventing shifting of the material relative to the apron in the depending portions of said festoons.

11. A drier for loose materials comprising a drying chamber, a conveyer comprising a pair of hanging freely between said laterally spaced means and means in and movable longitudinally of said drying chamber for supporting, maintaining and transporting said apron-supporting means in said relation in and through said dry- 5 ing chamber.

ALPHEUS O. HURXTHAL. 

